Your "ferritin" level might be the missing clue to why you're exhausted.

I spent three years blaming stress for my fatigue. My job was intense. I had two kids. Of course I was tired.

But it wasn't just tiredness. I also had brain fog, hair loss, and felt like I was running on fumes.

When I brought all these symptoms to my doctor together, something finally clicked.

She ordered a "complete iron panel," which included something called ferritin.

My iron levels? Normal. My ferritin? 18 (optimal is 50+).

Turns out, my body had enough iron circulating in my blood to do its job today.

But I had almost nothing stored!

I was running on fumes. The tiredness wasn't stress. It was biochemistry.

Within three months of addressing my ferritin, the fog lifted. I could actually get through a day without needing a nap.

I asked my doctor why we didn't catch this before.

She said, "Most annual physicals only check 'serum iron' or 'total iron,' not ferritin.

And unless you ask, insurance usually won't cover the full panel."

Think of your body like a car with a gas tank.

Serum iron is the gas in your engine right now.

It's the iron actively working in your blood, delivering oxygen to your cells. Your doctor checks this, and if it's normal, they assume you're fine.

Ferritin is the gas in your reserve tank. It's the iron your body stores for future use.

When life gets stressful, when you exercise hard, when you lose blood (especially during periods for women), your body dips into the ferritin tank to keep up.

Here's the problem: your serum iron can look fine while your ferritin tank is nearly empty.

You're driving around on fumes.

When your body is constantly pulling from an empty ferritin tank, everything suffers…

Most insurance companies won't cover a ferritin test unless you already have diagnosed anemia. So even if your doctor suspects it, they often can't order it without a fight.

And honestly, most doctors aren't trained to think about ferritin as a symptom tracker the way a functional medicine practitioner might.

They think about it as "disease yes/no."

But you don't have to wait for your doctor to suggest it.

You can ask for this specific test, or you can just get it as part of a complete baseline.

Function Health includes Ferritin as a standard marker in every membership.

They understand that energy is a vital sign, not a luxury.

By testing Ferritin alongside a full thyroid and blood panel, they catch the "invisible" causes of fatigue that standard physicals miss.

If you're tired of being told 'you're fine' when you don't feel fine, getting this data is the first step to actually fixing the problem.

You bring the numbers to your doctor, and suddenly you have a treatment plan instead of a dismissive pat on the back.

Learn more about Function Health here

Your body keeps score in ways you can measure. Sometimes the answer isn't "you need more rest." Sometimes it's "you need more iron storage."